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(No Model.) 4 sheets- Sheen 1.

G. S. STRONG.

VALVE MOTIONPOR STEAM BNGNEs. No. 304,970. l Patented Sept. 9, 1884. 1 l

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(No Modem 4 sheets-Sheet 2. G. S. STRONG.

VALVE MOTION POR STEAM ENGINES. Nq. 304.970. Patented sept. 9, 1884.

(No Model.) 4 Sheets-Sheet 3. G. S. STRONG.

VALVE MOTION FOB. STEAM ENGINES.

,970. Patented Sept. 9,1884.

WTNESSES" (No Moael.) 4 sheets-sheet 4. G. S. STRONG'.

VALVE MTI'N FOR STEAM ElTGIllES.

Patented Sept. 9, 1884.

N. Firms. Pmuvlmmgnpmf, vlamingtnn. 9.(1.

, NrrED STATES PATENT OFFICE.

GEORGE S. STRONG, or PHILADELPHIA, PENNSYLVANIA, ASSTGNOR To i JOHN T.MORRIS, TRUSTEE, OE SAHE PLAOE.

VALVE-MOTION FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 304,970, datedSeptember 9, 1884.

Application filed January 19, 1884. (No model.)

To all whom t may concern:

Be it known that I, GEORGE S. STRONG, a citizen of the United States,and a resident of Philadelphia, Pennsylvania, have invented certainImprovements in Valve Motions for Steam-Engines, of which the followingis a specification.

My invention consists of valve-gear, too fully explained hereinafter toneed preliminary eX- planation, to be used in connection with eitherlocomotives, stationary or marine steam-engines, the main objects of myinvention being as follows: First, to enable the engineer to stop,start, and reverse an engine with slight exertion; second, to permit theuse of a governor, in the case of a stationary or marine engine, toregulate the movement of the valve; third, to obtain the desired lap,lead, and cut-oft' of the valve to insure the quick admission of steam,and at the same time a long-continued opening of the exhaust; and,fourth, to avoid extended frictional surfaces in mechanism for operatingthe valves of a steam-engine.

In the accompanying drawings, Figure 1, Sheet 1, is a side view of myimproved valvegear as I prefer to make it; Fig. 2, a top view of Fig. l;Fig. 3, an end view of Fig. 1, looking in the direction of the arrow;Fig. 4, Sheet 2, a view of my improved valve-gear in its simplest form;Fig. 5, a diagram illustrating the action of the gear, Fig. 4; Fig. 6, adiagram illustrating the action of the gear, Fig. 1; Fig. 7 Sheet 3, agenera-l diagram illustrating the action of my improvedvalve-gear; Figs.8 and 9, Sheet 4, diagrams illustrating the result ot' my improvedvalve-gear on a valve and parts of the valve-seat.

Referring in the first instance to Figs. 1, 2, and 3, Sheet 1, Arepresents part of the counecting-rod of a steam-engine, B the valverod,and D a fixed Segment, made in the are of a circle and secured to anyavailable fixed'part ofthe engine, the dotted line .r representing thecentral line of the engine-that is, a line passing through the center ofthe crank-shaft and that of the cylinder. It is also the central line ofthe connecting-rod when the crankpin is either at its rear or frontdead-center,

the crank-pin being supposed to be at its rear dead-center in Fig. 1.` Ablock, E, istted 'to and arranged to be adj usted ou the segment,

and one end of a link, F, is connected to this block by a pin, a, theopposite end of the said link being connected by a pin, b, to a lever,H, which has a short arm, b, connected by a pin, d, to one end of a rod,G, the opposite end of the latter being connected by a pin, e, to thevalve-rod B, which is also connected by a pimf, to the upper'end of therocking' link I, the lower end ot' the latter being hinged by a pin., h,to any available fixed part of lthe engine. The purpose of this rockinglink is to support the end of the valve-rod and that of the rod G whenthezwo are connected together. A lever, K, is hinged by a pin, fi, tothe connecting-rod A oi' the engine, and one end of the lever H isconnected by a pin,j, to the said lever K, the latter being alsoconnected by a pin, m, to'one end of a radius-rod, M, the opposite endof which is hinged to any iixed part of the engine at the pointindicated in the diagram Fig. 7.

In explaining the operation of the abovedescribed valve-motion and therelation of the several parts to each other, it will be necessary torefer from time to time to the diagram Fig. 7, Sheet 2.' The line .friut-his diagram is the centra-lline of the engine, and corresponds withthe dotted line x in Fig. 1, the circle Y indicating the path of thecenter of the crank-pin, and the two diagonal lines A A showing the twoeXtreme positions of the center of Jthe connecting-rod A.

In Fig. 1 the crank-pin of the engine is, as before remarked, supposedto be at its rear dead-center, by which I mean that the said pin is atits nearest point to the cylinder of the engine, the piston being at therear end of the same, this posit-ion of the crank-pin being marked No. 1on the circle Y of the diagram. Vhen the crank-.pin is in this position,the

pin z' will be in a dotted line, (also marked No.

1 in Fig. 1,) its position in the diagram being indicated by the samenumber on the central line, as, of the engine. The block Eis midwaybetween the two extreme points of its adjustment-that is to say, theblock is at the point known to engineers as mid-gear. Vhcn the crank-pinhas been moved in the direction of the arrow in the diagram until it isat its outward dead-center-that is, at No. 25 ofthe diagram-the pin iwill be at the point marked with the corresponding number, 25, in Fig.l, and the central line ot' thelever H will bc in the position indicatedby the dotted line H. The point where the two diagonal dotted linesindicating the two extreme positions of the lever H meet in a line, 0c',drawn through the center -of the pin m and through a point, t, midwaybetween the two positions l and 25 in the said line nis the center ofthe segment D and the center of the fulcrum-pin b, which will be in thesame positionwhen the crank-pin is atits rear dead-center as itis whenthe crankpin is at its front dead-center.

Referring again to the diagram Fig. 7, it will be seen that the pin i ofthe connectingrod traverses in the path indicated by the oval iigure M,the pin traversing the lowerportion ot' this path, while the crank-pinis moving in the circle Y from its rear dead-center, No. l, to its frontdeadcenter, 25, in the direction of the arrow, and the pin i traversingthe upper half of the path when the crank-pin is returning from 25 toNo. 1. The pin j, however, which connects the lever K to the lever H,traverses the path indicated by the irregular oval figure N. Hence thepin b will, when the block E is at mid-gear, move up and down in the arcw w of a circle, this arc being indicated by a dotted line in Fig. l andby a plain line in Fig. 5.

Turning now to Fig. 4, which represents the valve-motion in its simplestform, and in which the block E has been raised on the segment D, it willbe seen that the pin b is connected to the valve-rod, the lever H havingno short arm b and no pin d, and consequently becoming a simple link. Inthis case, when the block is at mid-gear, there will be no movementwhatever of the valve-rod, the pin b traversing in the arc w w, Fig. 5;but when the block has been adjusted to its lowest point the pin willtraverse in the arc w w', Fig. 5, and the valve will have'its fullthrow. Should the block be adjusted to the position shown in Fig. 4, thepin I) will traverse in the arc 202 102, Fig. 5, the motion of the valvewill be reversed, and will still have its full throw, but cannot haveany lead, no matter what position the block E ocpies. This modication ofmy invention may, however, be used on engines in which the lead ofthcvalveis obtained by mechanism outside ofthe valve-operatingmechanism. In most eases, however, it will be desirable to make thevalve-motion as shown in Fig. l, and as illustrated in the diagram Fig.7, so that two movements of the valve may be obtained, one being theusual reciprocating movement or throw of the valve, the other being'amovement relating to the lap-lead and cut-off of the valve, which I willproceed to describe.

In Fig. l the pin b is moving in the arc w w lof a circle the center ofwhich is in the center of the pin a in the block E; but the lever H, otlwhich the said pin I) is the fulcrum, has an arm, b', carryinga pin, d,which is connected .to the valve-spindle, and this pin must have avibration from l to 25, Fig. 7, the pin being at the point l when thecrank-pin is at l in the diagram Fig. 7, and at 25 when the crank-pin isat its correspondingnumber, and hence the pin d, instead of traversingin the arc w w of a circle in the diagram Fig. 5, will pursue a courseindicated bythe margin of the black igure in the diagram Fig. 6, andtherefore there will be a movement of the valve even when the block E isat mid-gear; but this movement relates entirely to the lap and lead ofthe valve. When it is desired to give the average full throw to thevalve, the crank still turning in the direction of the arrow, Fig. 7,the block E must be depressed on the segment so that the pin c will bemoved from the point e in the diagram Fig. 7 to the point z2, when,although the pin d will continue to traverse a path of the formindicated by the margin of the black figure, thc position of the pathwill be changed to that indicated by the irregular figure XV in thediagrams Figs. 6 and 7, and the result will be an extended movement of'the valve, due to the vibration of the short arm b of the lever H, andthis movement may be reduced to any eXtent desired by adjusting theblock E on the segment toward its original mid-gear position. Vhen theengine has to be reversed, the block E should be adjusted in a contrarydirection on the segment so adjusted-forinstance, that the pin a will bemoved from the point z in the diagram Fig. 7 to the point z', when thepath traversed by the pin d will be again changed, this time to theposition indicated by X in the diagrams Figs. 6 and 7, and there willconsequently be a reversal of the engine. It will now be seen that acompound IOO movement is imparted to the lever H-namely, first, avibrating movement on its fulcrumpin I), and, second, a movement of thelever by which, under the control of the rod F, the fulcrum-pin iscaused to traverse in the are of a circle. To this second movementis duethe throw of the valve, the extent and direction of. the throw beingdetermined by the adjustment of the block on thc segment. To the firstmovement-that is, to the vibration of the lever on its fulcrum-pin-isdue the laplead and cut-off of the valve.

Vhile different kinds of Valves may be used in connection with theabove-described movements, I will explain the result attained by thesaid movements in connection with the valve shown in Figs. 8 and 9,Sheet 4, the valve in both eases being supposed to be at its full throw.

On the line l, Fig. 8, is shown the position of the valve in relation tothe steam-ports p q and exhaust-port s of the cylinder when thecrank-pin is at its rear dead-center-that is, at No. 1 in the diagramFig. 7. The valve,

IIO

2i, are indicated the different positions of the valve at the differentparts of the movement of the crank-pin indicated by correspondingnumbers on the circle Y in the diagram Fig. 7.

It will be seen'that the steam-port p is at its fullest opening on theline 7, and this will be the case when the crank-pin has reached thepoint 7 in the circle Y on the diagram Fig. 7, thus indicating a quickopening ofthe valve and a quick admission of steam during the early partof the movement of the piston, which is one ot' the objects of myinvention. Atthe same time the exhaust is not closed until the crank-pinhas nearly reached its front dead-center. This will be seen by referringto the position of the valve on the line 24 in Fig. 8. Thelong-continued opening of the exhaust is anotherimportant object of myinvention. Vhen the crank-pin has reached the front dead-center, thevalve will be in the position shown on line 25, Fig. 9, and will bearprecisely the same relation to the steamport q as it did to thesteam-port p when the crank-pin was at its rear dead-center. The coursepursued by the valve in its relation to the steam-port q during thereturn ofthe crankpin from 25 to 1 is indicated in the diagram Fig. 9,and will be readily understood by reference vto the said diagram, whichshows that there will be the same quick admission of steam andlong-continued opening of the eX- haust during the return movement ofthe piston as there was during its forward movement.

Referring back to Fig. l, it will be seen that the pin e, which connectsthe rod G to the valve-spindle B, is at a distance from the pin f, whichconnects the upper end of the rocking link I to the said valve-rod-anarrangement which I have found in practice to be the best for insuringan accurate movement of the valve.

Vhatever may be the position of the blockE on the segment, it maybe saidto be locked by the latter as against any shocks or jars, technicallytermed backlash,7 due to the movement ofthe parts connected with theblock, and hence the block can be easily adjusted on the segment', thebacklash or strains on the block presenting no impediment to its freeadjustment. For this reason, if the block is connected to the starting,stopping, and reversing gear of a locomotive, but little exertion isdemanded from t-he engineer in performing these duties. The easyadjustment of the block, moreover, is a matter of importance if it isconnected to the governor ot' an ordinary en`- gine and it may beremarked here that if the valve-gear is applied to an engine thecrankshaft of which has never to be reversed t-he segment D may be ofmore limited extent, as the block will not require to be adjusted tomore than half the distance required in an engine which has to bereversed.

Another prominentadvantage of the improved valve-gear, when applied toalocomotive, is that it may be arranged in any position desired inrespect to the driving-wheels, for, no matter what this position or thatof the stopping, starting, and reversing lever may be, mechanism forconnecting the said lever to the sliding` block can always be arrangedto clear the driving-wheels, the valve-gear being entirely outside thesaid wheels.

I have not shown any'connection to theblock for adjusting the same otherthan links V, to be connected to any operating mechanism which thecharacter of the engine may suggest.

I claim as my invention- 1. rIhe combination, in valve-gear forsteamengines, of the following elements, namely: tirst, a iiXed segment,D, and a block, E, adjustable thereon; second, a lever or link, I-I, andconnecting-rod A, lever K, and rod M, for imparting the within describedcompound movement to the said lever H; and, third, a rod, F, connectingthe adjustable block to the pin b of the lever or link, to which leveris also connected the valve-rod, substantially as set forth.

2. The combination, in valve-gear for steamengines, of the followingelements-namely: first, a xed segment, D, and a block, E, adjustablethereon; second, arlever, H, having its fulcrum-pin connected to thesaid block,

and having an arm, b, connected to the valvespindle; and, third, theconnecting-rod A, lever K, and rod M, forimparting the withindescribedcompound movement to the said lever H, all substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEO. S. STRONG.

Vitnesses:

JOHN M.' CLAYTON, HARRY SMi'rH.

